基于一维高阶梁理论的薄壁箱梁非线性弥散波特性  

Nonlinear dispersion wave characteristics of thin-walled box beam based on 1D higher-order beam theory

作　　者：谭敏尧 郭德全[1] 杨强[1] 杨莉[1] 罗德宁 TAN Minyao;GUO Dequan;YANG Qiang;YANG Li;LUO Dening(School of Automation,Chengdu University of Information Technology,Chengdu 610225,China)

机构地区：[1]成都信息工程大学自动化学院,成都610225

出　　处：《振动与冲击》2023年第21期126-132,共7页Journal of Vibration and Shock

基　　金：成都信息工程大学科研基金(KYTZ202146);四川省科技厅项目(2023YFN0009,2023YFG0046)。

摘　　要：当薄壁箱梁在受到动扭转载荷时,其截面产生翘曲和畸变形变且同时与扭转形变产生耦合。由于耦合效应的影响,应力波沿薄壁箱梁轴线的的传播变得很复杂。然而,现在对弥散现象的研究还不够深入,用三维弹性动力学方程的数值解很难观察出频散曲线各分支之间的相互关系。因此,采用能够表达这3种位移形变的一维高阶梁理论来研究色散关系。通过该研究,揭示了低频频散关系的虚、实分支之间的相互联系。在算例分析中,研究了薄壁箱梁几何效应引起的非线性色散影响,可知薄壁箱梁壁厚越大其极限波速越小;横截面宽高比越大,分支1的频率越大,而分支2和分支3的频率越小。When thin-walled box beam is subjected to dynamic torsional load,its cross-section undergoes warping and distortion deformation,they are coupled with torsional deformation.Due to coupling effect,propagation of stress waves along thin-walled box beam axis becomes very complex.However,at present,study on dispersion phenomena is not deep enough,and it is difficult to observe inter-relations among various branches of dispersion curve by using numerical solutions of 3D elastic dynamic equations.Here,the 1D higher-order beam theory being able to express the 3 kinds of displacement deformations was used to study dispersion relation.The study revealed inter-relations among imaginary and real branches of low-frequency dispersion relation.In numerical example analyses,the nonlinear dispersion effect caused by the geometric effect of thin-walled box beam was studied.It was shown that the larger the wall thickness of thin-walled box beam,the smaller the beam ultimate wave velocity;the larger the width-height ratio of cross-section,the larger the frequency of branch 1 and the smaller the frequencies of branch 2 and branch 3.

关 键 词：薄壁箱梁 扭转 翘曲 畸变 弥散效应 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]